Don't overtip. Even if the exchange rate has you feeling like you're the Sultan of Brunei (or at least wealthier than you are at home), curb the urge to pass on your perceived riches. Not only does it toss a wrench in the local economy, but it also spreads the notion that Americans have excess money to throw around and can often seem like charity. If you feel like you've received exceptional service and want to add a little more money to your tip, give it discreetly and directly to the person who assisted you.

Whenever possible, always tip in cash. According to guidebook guru and TV personality Rick Steves, lots of European countries consider tips to be their drinking money. It often takes a few days for servers to receive their credit card tips, if at all in some places. But cash assures that they have money to spend on a few fizzy cocktails, and may even be able to purchase a round or two for friends.

Tip in the local currency. Although some countries may prefer tips in U.S. dollars for the exchange rate, many residents may find it to be more of a hassle than a boon. Tipping in the local currency also allows you to keep better track of your spending as a whole, and eliminates any uncertainties.

Do a little extra research when it comes to all-inclusive tours. Find out if tipping is included and if so, whether this includes everyone from the tour guides to hotel housekeeping. Unfortunately, “all-inclusive” sometimes leaves certain service individuals overlooked. If you'd like to show your appreciation in the moment, a few extra dollars (or their equivalent) can go a long way.

Check whether a service charge has been added to your bill. While countries from Sweden to Switzerland are known to tack on service fees that takes the place of traditional tipping, it's also occurring in countries where tipping is uncommon: for example, South Korea's high-end hotels. Avoid double-tipping by always checking first.

In countries where tipping isn't expected, tourist areas and urban centers often follow their own set of rules. Expect to leave a few extra pounds if you're in London, but not when you visit the Cornwall countryside.

Similarly, in countries where tipping isn’t common practice, tipping your tour guide is the exception—their expertise goes a long way toward making your trip memorable. The equivalent of $8-$10/day (and $2/day to the driver, if it's a bus tour) is typical.

The universal rule: While tipping etiquette varies across the globe, giving a dollar or two to hotel porters and leaving a little something for housekeeping staff is the overall norm wherever you go.

Not sure how much to tip when traveling abroad? This guide will help you sort it out.

Via

How Much to Tip in the U.S.

Remember, the U.S. is the gold standard when it comes to tipping. Almost no other country's service industry relies so heavily on tips for a livable income, and while some places—such as San Francisco's Zazie restaurant—are doing away with tipping entirely, it remains a huge part of our culture. With so much fluctuating info, it's sometimes difficult to known how much to tip the pizza delivery person or whether to tip your Uber Eats courier. Here's a handy tipping guide to make things easier:

Restaurant servers: 15-20 percent of the bill (though 18 percent and above is increasingly standard). Many U.S. servers make $2.13 an hour and depend on tips for their livelihood. If they show you some love, reciprocate.

Bartenders: $1 per drink is standard when ordering at the bar (though if that cocktail you've ordered is complex—say, with muddled mint or frothed egg white—put down $2), or 15-20 percent of the overall tab.

Baristas: A few coins for a simple coffee or snack, a dollar and up for more complex orders.

Uber & Lyft drivers: While tipping Uber drivers was originally discouraged, both services now allow riders to tip in cash or via their apps for a limited time post-trip (saving folks like my dad from that “what to do” agony). The amount remains up to you, but consider tipping the same as taxis: 15-20 percent. For short trips, this equates to a dollar or two at most. The same goes for Uber Eats, where tipping is not required, but appreciated.

Pizza and other restaurant deliveries: 15 percent for standard service.

Take out: Tipping is not expected, but some customers like to leave a dollar or two.

Movers: $10-20 per mover for lighter, half-day moves; $40 per mover for a full-day. With multi-day, long-distance moves the tip is often incorporated into the overall fee, so check beforehand.

Hotel porters: $1-2 per bag.

Hotel housekeeping: $2-5 per night, left each morning with a note and/or in an envelope so that the intended person receives it.

Hotel concierge: $5-10, depending on the service.

Valet: $5-10 at pick-up.

The Vacation Experts at AAA can help plan your trip and answer your travel questions. It's a free service for AAA Members.